Dual-phase synchronous buck controller for high-current rails
The Texas Instruments LM5642XMH/NOPB is a dual-phase synchronous buck controller that steps down a 4.5V to 36V input rail to a regulated positive output. The two interleaved phases share the load current, which cuts input ripple and lets you use smaller input capacitors than a single-phase design handling the same total current. With synchronous rectification built in, the external low-side FET replaces the catch diode, keeping efficiency above 90% across most of the load range.
Control features and output configuration
The controller includes current limiting, an enable pin for sequencing, and a soft-start ramp that prevents inrush on power-up. The two outputs are independently configurable, so one controller can generate two different positive voltages from the same input bus. Clock synchronization (clock sync = yes) lets you lock the switching edge to an external clock, which is handy when you need to place the switching noise in a quiet band for an RF or analog section sharing the board.